GB500922A - Improvements in or relating to automatic guns - Google Patents

Abstract

500,922. Automatic guns. WERKZEUGMASCHINENFABRIK OERLIKON. April 12, 1938, No. 11258. Convention date, Dec. 13, 1937. [Class 92 (ii)] An automatic gun, of the kind in which the breech-block 7 is not positively locked, is provided with a recoil spring 10 and two further spring systems, one of which catches the breechblock resiliently towards the end of the firing stroke while the other assists the recoil spring in accumulating energy after the breech-block has passed rearwardly beyond its initial or cocking position. In the form shown, the barrel 1, Fig. 1, is secured by a bayonet-joint to a guide-bushing 2 'which is connected to the fixed breech casing 5 by a further bayonet-joint. The breech-block is connected to two longitudinal bars 6 by a member 8 which slides in two longitudinal grooves in the breech casing. The forward ends of these bars are connected to a sleeve 11 which houses the recoil spring 10. Each bar contains a spring 13 the forward end of which bears against a bolt 12 and the rear end against a pin 14. In operation, the pins bear against shoulders 6a of the bars 6 when the breech-block is positioned forwardly of its normal or cocking position (shown in dotted lines) and the springs 13 are not compressed. When however, the breech. block, during recoil, moves rearwardly beyond this position, the pins 14 abut against a shoulder 5a on the breech casing and the springs are compressed. The second spring system comprises a number of springs 4 the forward ends of which bear against the bushing 2 while the rear ends abut against a slidably 'mounted member 3. The sliding movements of this member are limited by shoulders 5b, 2a. This member provides the resilient abutment 'for the breech-block when the latter approaches its foremost position. A pivoted member 18, Fig. 7, is provided for locking the barrel 1 and guide-bushing 2 to the breech casing 5. This member, which passes through a slot in the guide-bushing and engages with the barrel, is normally held in the operative position by the engagement of a handle 15 with a notch 5a in the breech casing. By exerting pressure on a button 16, the handle is released from the notch and can then be turned to withdraw the member 18 from the slot in the guide-bushing.